This invention relates to the construction of sewing machine needle vibrating gates which are mounted so as to impart lateral zig zag stitch forming movements to the sewing machine needle. More particularly this invention relates to such needle bar gate construction provided with clearances to accommodate thermal expansion and wear of the parts, and a novel lost motion compensating arrangement for eliminating backlash and adverse influence on the zig zag stitch forming movements due to clearances in the needle bar gate mounting.